Why my iPhone shows headphones are always plugged in?

Yesterday I installed iOS 11.1.1 and since this morning I can’t listen anything by my handset. When i call I have to use the speaker and to listen voice notes I have to plug in the headphones because when I try to turn on the volume, it appears as headphones were plugged in, so the speaker won’t work in that case also. Can anyone help me? I tried turning off the iPhone, plugging and unplugging the headphones, normal ones and with USB adapter and anything works.